1. Field of the Invention
The present invention relates to a ball bearing, and more particularly to a ball bearing in which an annular cage having cylindrical pockets radially passing through the annular cage is guided by one of bearing rings.
2. Description of the Related Art
In a ball bearing, in general, an annular cage having pockets in several positions in a circumferential direction is incorporated between a pair of bearing rings disposed inside and outside in a radial direction. A ball is housed in each pocket of the annular cage.
There are annular cages of a type guided by balls and of a type guided by an inner ring as an inside bearing ring or an outer ring as an outside bearing ring. Normally, the annular cage of the latter type guided by the outer ring is selected for use for high-speed rotation.
The present inventor examined states of vibration and a temperature rise of the ball bearing of the type in which the annular cage is guided by one of the bearing rings. As a result, the vibration and temperature rise were liable to be generated when a radial clearance (guide clearance) of the annular cage with respect to the one bearing ring was set to be larger than an axial clearance or a circumferential clearance (pocket clearance) of a pocket inner wall face with respect to the ball.
In other words, as a result of eccentric rotation of the annular cage due to centrifugal force in the high-speed rotation, the inner wall face of the pocket interferes with the ball from the radial or circumferential direction. Therefore, each ball advances and lags. As a result variations in a pitch error of the balls increase to thereby cause a minute slip of the ball, which leads to generation of the above-described vibration and temperature rise.